package com.atguigu.gulimall.seckill.service.impl;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.to.mq.SeckillOrderTo;
import com.atguigu.common.utils.R;
import com.atguigu.common.vo.MemberRespVo;
import com.atguigu.gulimall.seckill.feign.CouponFeignService;
import com.atguigu.gulimall.seckill.feign.ProductFeignService;
import com.atguigu.gulimall.seckill.interceptor.LoginUserInterceptor;
import com.atguigu.gulimall.seckill.service.SeckillService;
import com.atguigu.gulimall.seckill.to.SeckillSkuRedisTo;
import com.atguigu.gulimall.seckill.vo.SeckillSessionsWithSkus;
import com.atguigu.gulimall.seckill.vo.SeckillSkuVo;
import com.atguigu.gulimall.seckill.vo.SkuInfoVo;
import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.aspectj.weaver.ast.Var;
import org.redisson.api.RSemaphore;
import org.redisson.api.RedissonClient;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 * @author tianxinyu
 * @create 2021-01-06 11:18
 */
@Slf4j
@Service
public class SeckillServiceImpl implements SeckillService {
    @Autowired
    CouponFeignService couponFeignService;
    @Autowired
    StringRedisTemplate redisTemplate;
    @Autowired
    ProductFeignService productFeignService;
    @Autowired
    RabbitTemplate rabbitTemplate;

    @Autowired
    RedissonClient redissonClient;

    private final String SESSION_CACHE_PREFIX = "seckill:sessions:";
    private final String SKUKILL_CACHE_PREFIX = "seckill:skus";
    //商品随机码
    private final String SKU_STOCK_SEMAPHORE = "seckill:stock:";

    @Override
    public void uploadSeckillSkuLatest3Days() {
        //扫描最近三天需要参与秒杀的活动
        R session = couponFeignService.getLates3DaySession();
        if(session.getCode() == 0){
            //上架商品
            List<SeckillSessionsWithSkus> sessionData = session.getData(new TypeReference<List<SeckillSessionsWithSkus>>() {
            });
            //缓存到redis

            //缓存活动信息
            saveSessionInfos(sessionData);
            //缓存活动的关联商品信息
            saveSessionSkuInfos(sessionData);



        }
    }

    /**
     * 返回当前时间可以参与的秒杀商品信息
     */
    public List<SeckillSkuRedisTo>  blockHandler(BlockException e){
        log.error("getCurrentSeckillSkusResource 被限流了 .... ");
        return null;
    }
    @SentinelResource(value = "getCurrentSeckillSkusResource",blockHandler = "blockHandler")
    @Override
    public List<SeckillSkuRedisTo> getCurrentSeckillSkus() {
        //确定当前时间属于哪个秒杀场次
        //1970
        long time = new Date().getTime();

        Set<String> keys = redisTemplate.keys(SESSION_CACHE_PREFIX + "*");
        for(String key : keys){
            //seckill:sessions:1609891380000_1609891500000
            String replace = key.replace(SESSION_CACHE_PREFIX, "");
            String[] s = replace.split("_");
            long start = Long.parseLong(s[0]);
            long end = Long.parseLong(s[1]);
            if(time>= start && time<= end){
                //获取这个秒杀场次需要的所有商品信息
                List<String> range = redisTemplate.opsForList().range(key, -100, 100);
                BoundHashOperations<String, String, String>  hashOps
                        = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
                List<String> list = hashOps.multiGet(range);
                if(list != null){
                    List<SeckillSkuRedisTo> collect = list.stream().map(item -> {
                        SeckillSkuRedisTo redis = JSON.parseObject((String) item, SeckillSkuRedisTo.class);
                        return redis;
                    }).collect(Collectors.toList());
                    return collect;
                }
                break;

            }

        }


        return null;
    }

    @Override
    public SeckillSkuRedisTo getSkuSeckillInfo(Long skuId) {
        //需要秒杀商品的key
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
        Set<String> keys = hashOps.keys();
        if(keys != null && keys.size()>0 ){
            String regx = "\\d_" + skuId;
            for(String key : keys){
                // 1_1
                if(Pattern.matches(regx,key)){
                    String json = hashOps.get(key);
                    SeckillSkuRedisTo skuRedisTo = JSON.parseObject(json, SeckillSkuRedisTo.class);
                    //随机码
                    long current = new Date().getTime();
                    if(current>=skuRedisTo.getStartTime() && current<=skuRedisTo.getEndTime()){
                    }else{
                        skuRedisTo.setRandomCode(null);
                    }
                    return skuRedisTo;
                }
            }
        }


        return null;
    }

    @Override
    public String kill(String killId, String key, Integer num) {
        MemberRespVo respVo = LoginUserInterceptor.loginUser.get();
        //获取当前秒杀商品的详细信息
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
        String json = hashOps.get(killId);
        if(StringUtils.isEmpty(json)){

            return null;
        }else{
            SeckillSkuRedisTo redis = JSON.parseObject(json, SeckillSkuRedisTo.class);
            //校验合法性
            Long startTime = redis.getStartTime();
            Long endTime = redis.getEndTime();
            long time = new Date().getTime();

            Long ttl = endTime - time;
            //校验时间的合法性
            if(time>=startTime && time <=endTime){
                //校验随机码和商品id
                String randomCode = redis.getRandomCode();
                 String skuId = redis.getPromotionSessionId()+"_"+redis.getSkuId();
                 if(randomCode.equals(key) && killId.equals(skuId)){
                     //验证购物数量是否合理
                     if(num<=redis.getSeckillLimit()){
                        // 验证这个人是否已经购买过，幂等性；如果秒杀成功就去占位
                         //SETNX
                         String redisKey = respVo.getId() +"_" + skuId;
                         //自动过期
                         Boolean absent = redisTemplate.opsForValue().setIfAbsent(redisKey, num.toString(), ttl, TimeUnit.MILLISECONDS);
                         if(absent){
                             //占位成功说明从来没有买过
                             RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + randomCode);

                                 boolean b = semaphore.tryAcquire(num);
                                 if(b){

                                     //秒杀成功
                                     //快速下单， 发送MQ 消息 10ms
                                     String timeId = IdWorker.getTimeId();
                                     //5.2 创建秒杀订单to
                                     SeckillOrderTo orderTo = new SeckillOrderTo();
                                     orderTo.setOrderSn(timeId);
                                     orderTo.setMemberId(respVo.getId());
                                     orderTo.setNum(num);
                                     orderTo.setPromotionSessionId(redis.getPromotionSessionId());
                                     orderTo.setSkuId(redis.getSkuId());
                                     orderTo.setSeckillPrice(redis.getSeckillPrice());
                                     //5.3 发送创建订单的消息
                                     rabbitTemplate.convertAndSend("order-event-exchange", "order.seckill.order", orderTo);


                                     return timeId;
                                 }
                                 return  null;


                         }else {
                             //说明买过了
                             return null;
                         }
                     }
                 }else{
                     return null;
                 }
            }else{
                return  null;
            }
        }
        return  null;

    }

    private void saveSessionInfos(List<SeckillSessionsWithSkus> sessions){
        sessions.stream().forEach(session->{
            long startTime = session.getStartTime().getTime();
            long endTime = session.getEndTime().getTime();
            String key = SESSION_CACHE_PREFIX+ startTime + "_" + endTime;
            Boolean hasKey = redisTemplate.hasKey(key);
            if(!hasKey){
                List<String> collect = session.getRelationSkus().stream().map(item ->item.getPromotionSessionId()+"_"+ item.getSkuId().toString()).collect(Collectors.toList());
                //缓存活动信息
                redisTemplate.opsForList().leftPushAll(key,collect);
            }


        });
    }
    private void saveSessionSkuInfos(List<SeckillSessionsWithSkus> sessions){
        sessions.stream().forEach(session->{
            //准备hash操作
            BoundHashOperations<String, Object, Object> ops = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
            session.getRelationSkus().stream().forEach(seckillSkuVo -> {
                //随机码 seckill?skuId =1 &key=
                String token = UUID.randomUUID().toString().replace("-", "");
                if(!ops.hasKey(seckillSkuVo.getPromotionSessionId().toString()+"_"+ seckillSkuVo.getSkuId().toString())){

                    //缓存商品
                    SeckillSkuRedisTo redisTo = new SeckillSkuRedisTo();
                    //sku的基本信息  skuInfo
                    R skuInfo = productFeignService.getSkuInfo(seckillSkuVo.getSkuId());
                    if(skuInfo.getCode() == 0){
                        SkuInfoVo info = skuInfo.getData("skuInfo", new TypeReference<SkuInfoVo>(){});
                        redisTo.setSkuInfoVo(info);

                    }
                    // sku的秒杀信息
                    BeanUtils.copyProperties(seckillSkuVo,redisTo);

                    //设置上当前商品的秒杀时间信息
                    redisTo.setStartTime(session.getStartTime().getTime());
                    redisTo.setEndTime(session.getEndTime().getTime());


                    redisTo.setRandomCode(token);

                    String s = JSON.toJSONString(redisTo);
                    ops.put(seckillSkuVo.getPromotionSessionId().toString()+"_"+ seckillSkuVo.getSkuId().toString(),s);

                    //引入分布式的信号量
                    RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + token);
                    //商品可以秒杀的数量作为信号量
                    semaphore.trySetPermits(seckillSkuVo.getSeckillCount());
                }




            });
        });

    }

}
